"Previous attempts at cloaking using a single meta-surface layer were restricted to very small-sized objects," said Zhi Hao Jiang, postdoctoral fellow in electrical engineering, Pennsylvania State University.

Jiang and Douglas H Werner developed a meta-material coating with a negligible thickness that allows coated objects to function normally while appearing as something other than what they really are, or even completely disappearing.

The researchers employ what they call "illusion coatings," coatings made up of a thin flexible substrate with copper patterns designed to create the desired result.

They can take a practical size metal antenna or sensor, coat it with the patterned film and when the device is probed by a radio frequency source, the scattering signature of the enclosed object will appear to be that of a prescribed dielectric material like silicon or Teflon.